Unveiling the Promoting Mechanism of H2 Activation on CuFeOx Catalyst for Low-Temperature CO Oxidation.

The effect of H2 activation on the performance of CuFeOx catalyst for low-temperature CO oxidation was investigated. The characterizations of XRD, XPS, H2-TPR, O2-TPD, and in situ DRIFTS were employed to establish the relationship between physicochemical property and catalytic activity. The results showed that the CuFeOx catalyst activated with H2 at 100 °C displayed higher performance, which achieved 99.6% CO conversion at 175 °C. In addition, the H2 activation promoted the generation of Fe2+ species, and more oxygen vacancy could be formation with higher concentration of Oα species, which improved the migration rate of oxygen species in the reaction process. Furthermore, the reducibility of the catalyst was enhanced significantly, which increased the low-temperature activity. Moreover, the in situ DRIFTS experiments revealed that the reaction pathway of CO oxidation followed MvK mechanism at low temperature (<175 °C), and both MvK and L-H mechanism was involved at high temperature. The Cu+-CO and carbonate species were the main reactive intermediates, and the H2 activation increased the concentration of Cu+ species and accelerated the decomposition carbonate species, thus improving the catalytic performance effectively.

Ultra-Reliable Deep-Reinforcement-Learning-Based Intelligent Downlink Scheduling for 5G New Radio-Vehicle to Infrastructure Scenarios.

Higher standards for reliability and efficiency apply to the connection between vehicle terminals and infrastructure by the fifth-generation mobile communication technology (5G). A vehicle-to-infrastructure system uses a communication system called NR-V2I (New Radio-Vehicle to Infrastructure), which uses Link Adaptation (LA) technology to communicate in constantly changing V2I to increase the efficacy and reliability of V2I information transmission. This paper proposes a Double Deep Q-learning (DDQL) LA scheduling algorithm for optimizing the modulation and coding scheme (MCS) of autonomous driving vehicles in V2I communication. The problem with the Doppler shift and complex fast time-varying channels reducing the reliability of information transmission in V2I scenarios is that they make it less likely that the information will be transmitted accurately. Schedules for autonomous vehicles using Space Division Multiplexing (SDM) and MCS are used in V2I communications. To address the issue of Deep Q-learning (DQL) overestimation in the Q-Network learning process, the approach integrates Deep Neural Network (DNN) and Double Q-Network (DDQN). The findings of this study demonstrate that the suggested algorithm can adapt to complex channel environments with varying vehicle speeds in V2I scenarios and by choosing the best scheduling scheme for V2I road information transmission using a combination of MCS. SDM not only increases the accuracy of the transmission of road safety information but also helps to foster cooperation and communication between vehicle terminals to realize cooperative driving.

Novel through-the-scope twin clip for the closure of GI wounds: the first experimental survival study in pigs (with videos).

BACKGROUND AND AIMS: We developed a through-the-scope twin clip (TTS-TC) for closing GI wounds. The objective of this study was to evaluate the efficacy and safety of the TTS-TC in GI wound closure. METHODS: GI nonperforating and perforating wounds (≥2.5 cm) were created in live pigs. TTS-TCs were used to convert the large wounds into small wounds. The remaining small wounds were closed using conventional through-the-scope clips (TTSCs). The follow-up period was 1 month. Location and size of the wound, time of wound closure, intraoperative and postoperative adverse events, and conditions of wound healing were investigated. RESULTS: Thirteen wounds were created in 5 live pigs, including 2 gastric nonperforating and 3 perforating wounds and 5 large intestinal nonperforating and 3 perforating wounds. The mean long and short diameters of the wounds were 4.1 (± .9) cm and 3.4 (± .7) cm, respectively. All wounds were successfully closed using the TTS-TCs combined with TTSCs. The total mean time for wound closure was 9.2 (± 5.3) minutes, and the mean time for using the TTS-TCs was 3.9 (± 4.7) minutes. During the 1-month follow-up period, no bleeding, perforation, or death occurred; all wounds healed with scar formation; and all TTS-TCs detached spontaneously. CONCLUSIONS: The TTS-TC was successfully used to close large-sized GI wounds. The TTS-TC is a promising tool for large-size wound closure under flexible endoscopy.

Effect of K-Modified Blue Coke-Based Activated Carbon on Low Temperature Catalytic Performance of Supported Mn-Ce/Activated Carbon.

To clarify the K modified effects over activated carbon (AC) supported Mn-Ce oxide catalysts, several Mn-Ce/AC and xK-Mn-Ce/AC mixed oxide catalysts prepared via an impregnation method supported on AC were investigated for low-temperature selective catalytic reduction (SCR) of NO with NH3 in the simulated sintering flue gas. The Mn-Ce/AC catalyst with a K loading of 8% showed the highest catalytic activity, corresponding to 92.1% NO conversion and 92.5% N2 selectivity at 225 °C with a space velocity of 12,000 h-1. Furthermore, the 0.08K-Mn-Ce/AC catalyst exhibited better resistance to SO2 and H2O than Mn-Ce/AC, which could convert 72.3% and 74.1% of NO at the presence of 5% SO2 and H2O, respectively. After K modification, the relative ratios of Mn4+/Mn n+ as well as Ce3+/Ce n+ and surface adsorbed oxygen increased. Additionally, the reduction performance of the catalyst was improved obviously, and both acid strength and quantity of acid sites increased significantly after the K species were introduced in Mn-Ce/AC. Especially, the NO adsorption capacity of the catalyst was enhanced, which remarkably promoted the denitration efficiency and SO2 resistance. The SCR of NO with NH3 on K-Mn-Ce/AC catalysts followed the L-H mechanism.